Dampening roll for lithographic presses



Aug, 9 1953 H. H. COLEHOWER, JR 2,549,649

DAMPENING ROLL FOR LITHOGRAPHIC PRESSES I Filed Dec. 29, 1948 mm aINVENTOR.

Harry H Colehowerjz A T T oRNEYs Patented Aug. 25, 1953 DAMPENING ROLLFOR LITHOGBAPHIC PRESSES Harry H. Colehower, Jr., Abington, Pa.,assignor to C. Walker Jones 00., Philadelphia, Pa., a corporation ofPennsylvania Application December 29, 1948, Serial No. 67,890

2 Claims. (01. 29-120) This invention relates to dampening rolls fordampening printing surfaces of lithographic presses.

It is known to provide dampening rolls for lithographic presses withcylindrical covers formed of woven fabric cut to size and seamed to forma tube of the proper diameter as well as plain knitted seamless coversand covers formed of terry cloth formed on circular knitting machines inthe form of sleeves knitted to the proper diameters and lengths whichwere slipped over the rolls, for example as disclosed in the patent toC. W. Jones, 2,149,606, issued March 7, 1939.

This invention has for its object the provision of a cover for dampeningrolls characterized by the fact that it will present a surface formed bynapping loop-s, interknitted with a seamless knitted fabric, in adirection longitudinally of the fabric.

The cover according to this invention will provide a soft, absorbentsurface over which the fibres formed by napping longitudinally of thecover will be evenly distributed and will effect an even distribution ofwater.

Referring to the accompanying drawings in which:

Fig. 1 is a perspective view of a dampening roll having a covering inaccordance with my invention;

Fig. 2 is a sectional view of a partially completed cover;

Fig. 3 is a view similar to Fig. 2 of a completed cover; and

Fig. 4 is an exploded perspective view of the cover in Fig. 3 lookingalong the axis of the cover.

Referring to Fig. 1 of the drawings, the reference character 2designates a conventional lithographing roll formed of suitable materialsuch as, for example, rubber, composition or any other suitable materialhaving a smooth cylindrical outer surface and provided with the usualshaft 4 and a seamless cover 6 having a contacting surface in accordancewith my invention,

The cover 6 is formed on a circular knitting machine of the well knowntype for forming terry cloth having an inner knitted body portion 8 andan outer body portion formed in series of loops interknitted with thebody portion 8 and presenting loops I which extend outwardly from thebody 8 as shown in Fig. 2.

The loops ID of the cover shown in Fig. 2 are napped in a directionlongitudinally of the cover or parallel with the axis thereof to form anap on the loops l0 extending longitudinally of the cover as shown at I2in Fig. 3. In other words,

2 the loops of the cover are napped in a direction parallel to the warpthreads.

The completed sleeves or tubes, comprising the cover, after completionare slipped on the roll in the usual manner.

The advantages of my invention result from the provision of seamlesscovers for dampening rolls for dampening printing surfaces onlithographic presses having a heavy napped surface formed of closelyarranged soft fibres extending from the loops ID in a directionlongitudinally of or parallel to the axis of the cover. The napped loopsill provide a contacting surface in which the napped fibres completelyobscure the loops and body of the sleeve and are evenly distributed overthe body portion, whereby a surface formed by the napped loops isprovided which will more evenly moisten the surfaces contacted therebyduring printing.

What I claim and desire to protect by Letters Patent is:

1. A dampening roll for lithographic presses comprising, in combination,a roller having a seamless terry cloth cover thereon, said cover havinga body of closely knitted fabric and a napped outer surface formed ofnapped loops interknitted with the loops of the body, with the napextending longitudinally of said cover and completely obscuring saidloops, said nap being evenly distributed throughout the circumference ofsaid cover to provide a surface adapted to contain water and evenlymoisten the surface contacted during a printing operation.

2. A cover for a lithographic press dampening roll comprising a seamlessterry cloth tube having a body closely knitted fabric and a napped outersurface formed of napped loops interknitted with the loops of the body,with the nap extending longitudinally of said cover and completelyobscuring said loops, said nap being evenly distributed throughout thecircumference of said cover to provide a surface adapted to containwater and evenly moisten the surface contacted during a printingoperation.

HARRY H. COLEHO'WER, JR.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 365,728 Carroll June 28, 1887 569,702 Wrightson Oct. 20, 18962,080,127 Goedike May 11, 1937 2,117,593 Backofen May 17, 1938 2,144,563Davis Jan. 17, 1939 2,149,606 Jones Mar. 7, 1939

